1. Field of the Invention
The present invention relates to a water-resistant slide fastener suitable for ski wear, sports bags, camping tents, etc. which require good resistance against rain and snow.
2. Prior Art
A known water-resistant slide fastener stringer, as disclosed in Japanese Patent Publication No. 46-17976, comprises a support tape and a row of coiled coupling elements mounted on one surface of the support tape; the support tape and the couping element row are covered by a layer of water-resistant elastomeric material. Such prior slide fastener is not suitable for sports bags, for example, because confronting contact edges of the opposed support tapes tend to be easily disengaged from one another when thrusting force is exerted on the support tapes from the interior of the bag due to over-packing, causing inadequate water-tightness.
U.S. Pat. No. 2,841,851 discloses a water-resistant slide fastener which comprises a pair of opposed sealing members of water-resistant elastomeric material, a pair of opposed upper stringers attached to the sealing members on respective upper surfaces thereof, and a pair of opposed lower stringers attached to the sealing members on respective lower surfaces thereof. Although it guarantees adequate water-tightness, the prior slide fastener has a very complex structure and therefore is not suitable for ski wear, sports bags, or camping tents which must be minimized in weight. Further, such complex slide fastener cannot be produced at low cost.
U.S. Pat. No. 4,112,150 discloses a method of manufacturing a continuous water-resistant slide fastener stringer. The prior method, however, comprises complicated and hence laborious processing steps which must be performed meticulously with a large scale and complex apparatus. With this method, it is difficult to coat water-resistant material over both the support tape and the coupling elements evenly. Therefore, satisfactory and uniform quality water-resistant slide fasteners cannot be produced.